hantek dso5072p sometimes is ok but sometimes only fan is on

[gromi_72]

Sometimes (especially after long time without using it) when i try to turn on oscilloscope it try to begin less than 1s and after that only fan is going on (the other things like buttons, leds and display are without reaction).
What can be there?
What should i try to find at the moment?
Maybe "alu" capacitors?
How can i try this.
Als attachment is a photo inside.

[gromi_72]

Now is even something special :)
fun on, some leds on, display off and everything without reaction

edit: about 10 minuts after this everything works good

[Microcheap]

Check the output voltages in the power supply to see if it is ok:



But according to the symptoms you described, I would suspect of bad electrolytic caps or some cold/cracked solder joint.

[gromi_72]

in 2 places was a difference:
-- pin 2 -- +15.3V instead of +14.5V +/- 0.5V
-- pin 6 -- -9.1V -- -9.0V instead of -7.0V +/- 0.5V
Every other voltage was very good.
Measurement after normal start of oscilloscope with uni-t UT70A.

EDIT:
Other (good) pins:
-- pin 4 -- +6.5V (+6.5V +/- 0.2V)
-- pins 9 and 10 -- +3.28V (+3.3V +/- 0.1V)
-- pin 12 -- +4.95V (+5.0V +/- 0.2V)

What can be wrong?

Thank you for this picture. Where can I find some other helpful data for my oscilloscope?

[Lew1]

Hello Guys,
I have basically the  same issue.  Only the fans runs.  My PS board has on it: DSO5000 Series Power, 2013/05 Ver 1.0.  Would anyone possibly have a schematic for this unit?   Any help would be greatly appreciated...

Thanks,
Lew1

[Syzeryuino]

have u fixed the issues? or do you just give up? because I have the same issues, same led lighting up and everything